A polymethyl methacrylate (PMMA) bone cement composition is widely used as a prosthetic material for a bone defective part, as an adhesive for fixing a metallic prosthesis such as a hip prosthesis to its surrounding bones, or the like. An existing PMMA cement composition containing a contrast agent such as barium sulfate or zirconium dioxide, however, does not have bioactivity, namely, bone bonding performance, and thus causes the following problem: loosening between a bone cement and the bone due to the course of a long period after application. In order to solve such a problem, there has been proposed a bone cement composition to which titanium dioxide particles are added for the purpose of imparting bioactivity (JP 2007-54619 A).
In recent years, vertebroplasty has been used as a fast-acting therapeutic method for alleviating pain due to compression fracture associated with metastasis of malignant tumors to the vertebral body or associated with osteoporosis. This method is a method for injecting a bone cement to a damaged portion of the vertebral body to reinforce the vertebral body. Since a fluid bone cement is directly injected into the vertebral body, the bone cement may be leaked from the damaged portion and the like to the outside of the vertebral body. Therefore, it is necessary to add to a bone cement a predetermined amount of an inorganic compound having radiopacity, such as barium sulfate particles or zirconium dioxide particles, and to make procedure, while an image obtained by an X-ray inspection apparatus being observed, so that the bone cement is not leaked (JP 2011-514818 A).